GAZA CITY, Gaza Strip — Several thousand Palestinians, defying the urging of Hamas to remain in their homes, fled areas in northern Gaza early Sunday after Israel warned them through fliers and phone calls of major attacks to come.

Israel and Hamas seemed to signal little public interest in international appeals for a cease-fire as they continued their barrages. More than 130 rockets were fired out of Gaza into Israel on Sunday, with 22 intercepted, the Israeli army said, while Palestinians expressed anger over the previous day’s Israeli strikes on a center for people with disabilities and on a home in an attack that killed 17 members of one extended family.

Early Monday, Israel also exchanged volleys with Lebanon, to the north, shelling it in response to a cross-border rocket attack, one of a string in recent days, Reuters reported. There was no word on damage or casualties.

Those fleeing northern Gaza traveled in vehicles, in donkey carts and on foot. Some waving white flags, residents of areas around Beit Lahiya ventured south to seek shelter in United Nations-run schools, cramming into classrooms and piling desks out on balconies.

“We left because of the terrifying bombing in the night and because of the fliers that warned that any moving body after noon will be struck,” he said.

The leaflets warned residents in the north to evacuate before what Israel’s military spokesman described as a “short and temporary” campaign against rocket launchers there. Hamas, which controls Gaza, asked residents to stay in their homes and ignore “Israeli propaganda,” but many fled anyway.

Al-Sultan looked over at the young woman next to him and said: “I don’t need another tragedy. This is the fiancée of my son.” Three days ago, the son, Odai, 21, was killed in an Israeli rocket strike on the taxi he was driving. Al-Sultan said that he had no idea why it had been attacked, and that it must have been the wrong car.

Isra Abbas, the fiancée, 17, was to marry Odai in September.

“The 1948 Nakba is now happening every four years,” she said angrily, referring to the Palestinian exodus, known as “the catastrophe,” during the Arab-Israeli war.

“We pray to God there will be a truce, for our children and ourselves,” al-Sultan said, looking around the crowded classroom. “We can’t live here. There are no beds and few bathrooms, and men and women are here together.”

EPA

An Israeli military unit near the border fired at targets in the Gaza Strip.

Down the hall, his nephew Muhammad al-Sultan, 26, had come with his wife and two young daughters on a donkey cart early in the morning after air attacks on his farmland. He conceded that many rockets were fired toward Israel from the area around Beit Lahiya.

“Many rockets go from there,” he said. “But Israel lands more on us.”

The assistant principal of the school arrived early Sunday morning, and the courtyard was already full of refugees, she said.

“It was a shock,” she said, estimating that for the 31 classrooms she had about 1,000 people. The principal, who said she had to turn one family away because the place was full, said she could not be quoted by name without U.N. permission.

According to Christopher Gunness, the spokesman for the U.N. Relief and Works Agency, or UNRWA, which deals with the refugees and operates the school, about 17,000 displaced people were already sheltering in 20 UNRWA buildings.

For Israel, poised between international appeals for a cease-fire and a decision on whether to send ground forces into Gaza, the goal now is to ensure a longer lull in Gazan rocket fire, which badly wounded a 16-year-old in Ashkelon on Sunday. That can be achieved only by seriously degrading Hamas’ fighting capabilities, whether by military means or through diplomacy, Israeli officials say. Part of the strategy, they say, is to cause “pain” to Hamas and its leaders, whose houses — even those without weapons stores — Israel is bombing here.

Prime Minister Benjamin Netanyahu of Israel, who appeared on U.S. talk shows on Sunday, emphasized that the Israeli army was “prepared for any possibility” and that Israel wanted “sustainable quiet.” Before the weekly Cabinet meeting, he said: “I don’t know when the operation will end. It might take much more time.”

There is little appetite for a return to the cease-fire of November 2012, which lasted about 19 months. Yuval Steinitz, the minister for strategic affairs, told Israel Radio that while the immediate goal was “quiet,” “the strategic goal is demilitarization.” He added, “We have to finally not be satisfied with a temporary filling, but do a root canal.”

AFP/Getty Images

Smoke billowed from buildings after an Israeli airstrike in Gaza City.

But as the bombing and rocketing continued, there was growing international pressure on Israel to settle for a cease-fire, called for by France, Britain and a nonbinding resolution of the United Nations. Those calls were intensified by the bombing that killed some of a center’s disabled residents early Saturday, and the funeral on Sunday for the 17 relatives who died in a bombing late Saturday when Israel tried to kill Gen. Tayseer al-Batsh, the Hamas police chief. Al-Batsh, who was seriously wounded, was visiting his aunt’s house, which was reduced to rubble, neighbors said, by bombs that sent body parts at least 100 yards.

Local officials and relatives searched Sunday for more bodies before burying the family, including seven children, and a neighbor in 18 graves dug in the same compound. Mahmoud al-Batsh, 48, a relative, said it was too dangerous now to bury them in the cemetery, which is near the border with Israel in northeast Gaza.

“The Jews don’t differentiate between the police commander and ordinary citizens,” he said. Some argued in the heat whether the row of graves, lined with concrete blocks, was sufficiently aligned with Mecca.

The attack left scores wounded by shattered glass and explosive compression. There was no warning, residents said; Israeli officials have said they do not warn prime targets whom they are trying to kill.

Munzer al-Batsh, the police commander’s brother and a gardener, said at the scene: “The Jews eliminated an entire family — grandfather, father, mother, even the children, who were sleeping in the homes. They were civilians.”

He said he had heard the bombs but could not see through the smoke and dust. When the air cleared, he said, “there was a three-story house wiped out.”

“I couldn’t remember at first that there was a house there,” he added.

The campaign’s death toll among Palestinians was 158, more than half of them noncombatants, and more than 1,100 people have been hurt, the Health Ministry said.

Abdallah al-Frangi, the Fatah official appointed governor of Gaza last month under a unity government established by the Fatah faction and Hamas, condemned the conflict, which he said Israel had started, and asked the United States to intervene.

“The Americans are the people who can do it if they want,” he said. “Netanyahu doesn’t want to negotiate with the Palestinians and doesn’t want a Palestinian state next door.”

Asked why he could not persuade Hamas to stop firing rockets, al-Frangi said: “We cannot ask Hamas while Israel is continuing this aggression. If Israel will stop, I’m sure Hamas will stop.”

Some Israeli security experts argue that Israel’s goals cannot be achieved without an invasion. If the objective is “to clean the territory,” said Gabi Siboni of the Institute for National Security Studies at Tel Aviv University, “the way to do it is to activate all your forces.”

Hamas has a huge arsenal of weapons of all types, including anti-aircraft and anti-ship missiles, besides thousands of remaining rockets, military officials said.

Hamas is also not an easy enemy to fight on the ground in an urban setting. It has built a network of tunnels and booby traps, and has long threatened to capture Israeli soldiers as bargaining chips for the release of prisoners.

But rocket launchers are hard to eliminate from the air. Most rockets are loaded underground and launched through narrow slits in the areas between crowded-together houses, and those who fire them enter and exit the tunnels from other houses.

Hamas has its own motivations, said Mkhaimar Abusada of Al-Azhar University here.

“Hamas has been politically isolated” since the military coup in Egypt last summer closed down smuggling tunnels and the Rafah border crossing, he said. And Israel tightened controls over Gaza after it discovered a Hamas tunnel into Israel six months ago, he said. At the same time, “the unity government with Fatah has done nothing for Gaza or Hamas,” which can no longer pay full salaries to its 40,000 employees.

“So Hamas’ main goal from this conflict is to end the siege,” Abusada said. “It can no longer survive this way, feeling suffocated by Israeli and blockaded by Egypt and ignored by Abu Mazen,” the Palestinian president, Mahmoud Abbas. For now, Abusada said, with Hamas political figures in hiding, the military wing is calling the shots. Any cease-fire deal, he said, will have to be done with the Hamas political chief, Khaled Meshal, who lives in Qatar.

As for a ground operation to destroy Hamas’ rocket capability, “Israel would have to go deep into Gaza, and that would be very costly to civilians, and I don’t think the United States and the West are willing to absorb that much bloodshed,” Abusada said.

Getty Images

In Sderot, Israel, a man held up a destroyed rocket, which he said was fired from inside Gaza toward Israel.

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